ios - 如何在 UI 中快速显示 JSON

Question

我尝试在 iPhone 上调整我的 Android 应用程序，但是当我要求我的服务器获取 JSON 对象时，出现 fatal error :

fatal error: unexpectedly found nil while unwrapping an Optional value

我认为我的 Storyboard或其他东西中的文本字段初始化不正确，但我找不到我的错误。

print(jsonResult) 为我提供了良好的 JSON，但在出现 fatal error 之后。

import UIKit

class ViewController: UIViewController {



@IBOutlet weak var labelCategory: UILabel!
@IBOutlet weak var imageViewOneTrash: UIImageView!
@IBOutlet weak var textFieldCoordinate: UITextField!
@IBOutlet weak var textFieldAddress: UITextField!
@IBOutlet weak var buttonShare: UIButton!
@IBOutlet weak var buttonCoppy: UIButton!
@IBOutlet weak var buttonDelete: UIButton!
@IBOutlet weak var buttonMaps: UIButton!
@IBOutlet weak var addressTxtFld: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    // 1
    let urlAsString = "http://www.website.sample"
    let url = NSURL(string: urlAsString)!
    let urlSession = NSURLSession.sharedSession()

    //2
    let jsonQuery = urlSession.dataTaskWithURL(url, completionHandler: { data, response, error -> Void in
        if (error != nil) {
            print(error!.localizedDescription)
        }

        // 3
        do{
            if let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as? [String:AnyObject] {

                print(jsonResult)
                // 4
                let jsonAddress: String! = jsonResult["trash_temp_address"] as! String

                dispatch_async(dispatch_get_main_queue(), {
                    self.addressTxtFld.text = jsonAddress
                })
            }

        }catch let error as NSError {
            print(error.localizedDescription)
        }

    })
    // 5
    jsonQuery.resume()

}

  override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

print(jsonResult) 的结果是:

["result": <__NSArrayM 0x15d62770>(
{
    "cat_name" = Mobilier;
    "country_name" = France;
    "town_name" = Toulon;
    "town_postal_code" = 83200;
    "trash_temp_address" = "278-338 Chemin du Jonquet";
    "trash_temp_date_time" = "2016-05-22 17:49:14";
    "trash_temp_fk_category" = 2;
    "trash_temp_id" = 99;
    "trash_temp_img" = "/pics/IMG_20160622_174846.jpg.png";
    "trash_temp_latitude" = "43.1395197";
    "trash_temp_longitude" = "5.9106404";
}
)
]

Answer 1

• 根对象是一个带有一个键result的字典。
• key result 的值是字典数组

这会获取键 trash_temp_address 的值

if let jsonRootObject = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String:AnyObject] { // mutable containers are not needed

    print(jsonRootObject)
    if let jsonResult = jsonRootObject["result"] as? [[String:String]],
       jsonAddress = jsonResult[0]["trash_temp_address"] {    
          dispatch_async(dispatch_get_main_queue()) {
             self.addressTxtFld.text = jsonAddress
          }
    }
    ...